Sealing assemblies intended to equip rolling bearings of hub bearing assemblies on the side of the flange which supports the wheel, so-called “outboard”, such as for example those described in U.S. Pat. No. 8,303,190 and in US2012/0177315, are formed by so-called “cassette” seals including a first and a second annular shield, generally L-shaped in radial section, mounted one facing the other so as to delimit, between the shields, an annular chamber in which a series of sealing lips is arranged carried by an annular seal secured integral to one of the shields, generally the shield intended in use to remain stationary. Access to this chamber by external contaminants (water, mud, dust) is limited by a particular conformation of the flange portions of one or both of the shields, which also cooperate, in very close manner, with radially outer portions of the outer or inner ring of the bearing and/or with elements of the hub bearing integral therewith, thus forming labyrinth seals.
Nevertheless, to date, the passage of external contaminants into the chamber has been in any event excessive and therefore sealing lips are all to exert a sliding seal on respective sealing surfaces of the rotating shield (or surfaces integral therewith) obtained by providing significant interferences of the sliding lips, which lips may vary in shape and possibly be spring loaded. This increases friction in a currently unacceptable manner.
Furthermore, the complex conformation of the shields increases costs, makes assembly operations more difficult and above all, significantly increases bulks, in particular in axial direction, of the sealing assembly. The sealing assembly according to JP2012/154374A does not solve these problems.